Download of ToneCalculator 4.0.6 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software relates to Productivity Tools. We recommend checking the downloaded files with any free antivirus. This free Mac app was originally produced by naiv.de.
From the developer:
ToneCalculator lets you tune your tempo, metronome, and fretboard for many instruments, scales, and tunings. It offers you the right means to bring your songs in tune. Thus, you can find the right tempo that fits best to your song. ToneCalculator also provides you with the correct (in sync) data for your Delays, LFOs, pre delay times of your reverb, attack and release times of compressors and other envelops.
You may want to check out more Mac applications, such as VAT Calculator, Geometry or CalcMadeEasy - Multipurpose Calculator, which might be similar to ToneCalculator.